A recent post at Signal vs. Noise asking about the merits of Rosetta Stone brought a number of entrepreneurs out of the woodwork to promote their own language learning tools.
Livemocha.com is a social network idea. The site provides free lessons, matches you up to chat with native speakers, and lets the community correct each other's writing and speaking samples. Available for 11 of the biggest languages.
Edufire is a marketplace for individual tutoring by live video chat. You select what you want to learn and then see a list of available tutors, with their hourly rate and amount of experience on the site.
Byki (Before You Know It) is software that appears superficially similar to Rosetta Stone, but they offer a free lite version, the full software for $50, and over 70 languages.
Universed collects resources for learning languages, organizing them by media type: bookmarks, videos, podcasts, and photos. I'm not sure precisely what the photos are supposed to do for you.
LingQ (pronounced "link") is a service with multiple price levels from free to $80/month, that also involves buying entire courses from personal tutors. It's based on the founder's own methods, which appear to involve things like marking the words you don't know in passages, getting back flash cards with those words, and then submitting writing samples to the tutor employing some of those words. Ten languages are offered, and there is supposed to be a community component as well.
Side note: It's problematic when a site has only a few public pages that seem totally disconnected from the real product, as if you are on the other side of the wall from the promised land. If you offer some level of service for free, there should be an easy way to try it out or demo it, without having to 'sign up.' Also, if you're claiming to have a community, you should offer some evidence of its actual existence, like Livemocha, which has random snapshots and user names on the front page.
Mango Languages offers Flash-based lessons in 10 languages. They have free and paid levels, and "Mango to go" for $150 which lets you download mp3s and PDFs. I'll bet they're working on an iPhone version, as the only portability the current product seems to buy you is not needing an internet connection.
Unilang is another community-based free site, similar to Livemocha, but with a wider variety of resources such as lessons, phrasebooks, videos, etc., in some cases created by users or adapted from other sources. With a quick look around I saw courses in Ainu, Catalan, Esperanto, and Mongolian, as well as more common choices.
Popling, for the ADD set, delivers pop-up vocabulary questions every so often, each of which you can choose to answer or ignore. Not a bad idea. There are seven languages plus chemistry and geography. You can pay $20/year for a few more features.
A lot of people also suggested Pimsleur audio courses, which I've never tried. Oh, and happy new year!